Electric signal system.



E. M. JONES. ELECTRIC SIGNAL SYSTEM. APPLICATION FILED JULY 13,1908.

N www E. M. JONES.

ELECTRIC SIGNAL SYSTEM. APPLICATION FILED JULY 13, 190s.

1,126,776. Patented Feb.2,1915.

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A'Tfrf UNITED STATES PATENT OFFICE.

ELMER M. JONES, OF ATLANTA, GEORGIA, ASSIGNOR TOl JONES SIGNAL SYSTEM COMPANY, OF ATLANTA, GEORGIA, A CORPORATION OF GEORGIA.

ELECTRIC SIGNAL SYSTEM.

Specification of Letters Patent.

Patented Feb. 2, 1915.

Appiication aiefi July i3, isos. serial No. 443,206.

To all whom it may concern Be it known that I, ELMER M. JoNEs,-a

citizen ofthe United States, residing atj Atlanta, in the county of Fulton and State of Georgia, have invented a certain new and useful Improvement in Electric Signal Systems, of which the following is a full, clear, and exact description, referencebeing had to the accompanying drawings.

The object of this invention is to provide a simple and efficient electric signal system adapted to give an indication either in a moving locomotive or along the trackway whenever the track ahead is obstructed or broken.

The invention is an improvement on that shown in my application Serial No. 425,821, filed April 8th, 1908.

One of the improvements of the present application provides for automatically advising an engineer who has been stopped by a danger signal the instant the track ahead of him becomes clear without requiring any manual test on his part. This, I accomplish either by making the contact plate long enough so that when an engineer stops inv pursuance of a danger signal, he will still be on the contact plate, or I provide, connected with the main contact plate', an advance plate, on which he may stop to receive his safety signal; or I provide, either as a substitute 'for this or an addition to it, a track semaphore. This track semaphore is preferably located just at the entrance to a block and has the additional advantage of giving a signal irrespective of any locomotive equipment, the signal being thus available for yard engines, hand cars, etc., as well as for watchnien at crossings.

Another feature of my invention, which is designed to render the application of the danger signal more certain should there be any breakage of the line or leakage between the contact plate and the rail, consists in supplying the current which holds the locomotive signal at safety from the track installation at the time the track conditions are tested, instead of by a battery on the locomotive, the result being that not only will any breakage in the line throw the locomotive signal to danger, but if there should be a short circuit by leakage or otherwise between the contact plate and the rail, the source of power will be short cireuited and the locomotive signal will go to danger.

This eliminates the possibility of the signal `being accidentally or maliciously rendered non-effective by cross connection between the contact plate and the rail.

Another feature of the present invention consists in arranging the short exposed contact members by which the locomotive operates the protecting relay in the form of additional contact plates, rather than short sections of rail, and I provide the loconiotive with a special brush adapted to bridge these contact plates and cross-connect them. This improvement makes a more positive operation than where short rail sections cross-connected by the wheels and axle of the locomotive are employed, inasmuch as the locomotive must be at a definite point when the cross-connection of contact plates takes place. .Moreover, it reduces the interference with the track iii installing the system and simplifies the insulation required.

Another feature of the invention consists in dividing the mechanical and electrical connection between the locomotive and track circuits so that brushes are used for the electric connection and levers to provide the mechanical movement for operating the circuit breakers, these levers being so arranged and conneetedrthat if they should accidentally stickin elevated position, a danger signal will almost immediately be given, apprising the engineer of the condition. I also providemeans whereby any short-circuit between tlie circuit breaking lever and the contacts when in open position would 'ground the locomotive battery, thus immediately giving a danger signal.

The above described features and other characteristics of the present improvement will be hereinafter more fully described. The invention may accordingly be characterized as consisting of the circuits and mechanism illustrated and summarized in the form of essential elements in the claims.

The drawings illustrate the invention in the form of diagrams.

Figure 1 is a diagram of the track equipment for one block, and portions of the two adjacent blocks. My track equipment is located adjacent to the two ends of the two blocks, and the intermediate portion of the intermediate block, which is shown as broken out` has continuous line wires, and the two adjacent blocks shown have their line wires continuous to points near their opposite ends. Accordingly, Fig. 1 represents the complete track equipment.V Fig. 2 is a simplified diagram representing the locomotive circuit and the means by which the locomotive signal receives current from the track, and by means oi' which the locomotive controls the protecting relay. The circuit breaking lever in this view is twisted at right angles to normal position to present it in the same plane wlth the rest of the diagram. Fig. 3 is a diagram representing the locomotive circuit and showing at once the circuit breaking levers on the two sides of the locomotive,-the far side of the locomotive truck being inverted to bring the parts into the same plane for clearness in the diagram. Fig. 4 is an enlarged representation of the Contact controlling portion of one of the circuit breaking levers. i

My system may operate either cab signals in moving locomotives or cars, or track semaphores, or both. It is show-n herein as operating both, magnets controlling both signals being in series on the same line eircuit.

For ready comprehension, I will describe first the locomotive circuit in a simplified form, then the track system, and finally the entire elaborate-actual equipment of the locomotive system shown in Figs. 3 and 4.

The locomotive circuit, as shown in Fig. 2, includes the line 3, magnet 2, line 4, battery 1 and line 5, which terminates at a contact member 6 which is normally in engagement with the contact segment 7 insulatingly carried on the operating lever 8 which is in engagement with the line 3. The mag-l -net and battery are thus in a normally closed circuit which operates to hold the signal at safety, the signal being indicated by a pivoted blade 9, which is suitably counter-weighted to give it a tendency to swing into a horizontal or danger position,

the magnet 2 serving to hold it normally in the depending or safety position. 4Any suitable connecting mechanism may be used between the magnet and the signal arm, or another form of signal may be operated by the magnet, as is well understood.

A branch line 10 leads from the normally closed circuit described to the frame, axle and wheels of the locomotive. The operating lever 8 is also normally grounded on such frame. From the line 3, a line 11 leads to one or more suitable contact brushes 12, hereinafter more fully described. These contact brushes are adapted to electrically engage elevated contact lplates along the trackway, and these contact plates are adapted to engage and swing the levers 8 to break the connection between the terminal 6 and the segment 7. It will accordingly be seen that whenthe brush 12 is on a contact plate and the circuit broken between 6 and 7, the magnet 2 will be denergized, allowing the signal to go to danger, unless another path and source of currentis provided, completing the circuit via the brush, contact plate and through the rails and track system to the locomotive wheels. As will be herein seen, my track system does provide such a -path -for the current, and such source of current whenever the track is clear but not when it is obstructed or broken.

I preferably employ two brushes 12, on each side of the locomotive, locating one in advance and one behi-nd the lever 8 so that whatever the direction of movement of the vehicle, lthe locomotive may make an electrical contact with the plate hereinafter described before tlie lever moves by mechanical contact with the plate, and may continue such electric connection after the lever has cleared the plate and returned to normal position. y

Other features of the locomotive circuit tending to increase the efficiency and certainty will be postpohed until after the track system has been described.

I will now proceed to describe the track system by reference to the diagram, Fig. 1. The track is divided into blocks, of which three are shown in this diagram, labeled A', A?, A3. Both rails ofthe track are preferably insulated between the successive blocks, as shown. The track system for each block comprises first a main normally closed circuit, including a portion of the track, a relay, a source of current and conductors; second, two line circuits, each controlled by the main circuit relay, one for the block at one end of that under consideration, and the other for the block at the other end, each line circuit having conductors, a source of current,and one or more magnets,and being controlled also by a protecting relay, hereinafter mentioned; third, two protecting relays for each block, each of which controls Y, i

a Corresponding line circuit, each protecting relay being provided with two magnets and two circuits for operating them, which circuits may be controlled by a passing locomotive; and finally, signalgiving means f controlled by the line circuit. For giving a cab-signal this means may consist of two contact plates for each block adapted for electric connection with the brushes of the locomotive and to swing the circuit breaking levers of the locomotive, each contact plate having a possible connection to the track under the control of a corresponding line magnet (and preferably also under control of the protecting relay) ,and having a source of current for operating the locomotive signal, when the circuit passes through such source of current. For giving a track signal a semaphore is employed controlled by a magnet in the line circuit. These various circuits are illustrated in Fig. 1, appertaining to the block A2. Considering the block A2, there will be seen near the left hand end of the block a main battery 30, on a line 31 leading from one sectional rail X to the other rail X. Near the other end of this block is a line 32 passing from the rail X through the main magnet or relay 33, and from this magnet a line 34 leads to the rail X. Accordingly there is here provided a normally closed main circuit including sub` stantially the whole of the block and having at one end of the block a magnet, and at the other end a battery. The magnet 33 is adapted to hold an armature 40 in` position to close two line circuits which lead in each direction from the block A2.

One of the line circuits referred to is composed of the armature 40, a. lineal which leads therefrom through an armature 42 of a protecting relay R3 (to be hereinafter described) to a line 43 having a battery 44, and thence continuing by the line 45 to a line magnet 46, from which a line 47 returns'through the magnet 48 for controlling the track signal, thence via the line 49 to the armature 40. Accordingly, there is a closed circuit from the armature 40 of the main magnet for block A2 through the armature of the protecting relay at the adjacent end of block A3, and thence through the line magnet 46 adjacent to the end of block A and through the semaphore magnet 48 substantially at the junction of the blocks Al and A2. The other line circuit for the block A2 starts from the contact strip 50, insulatingly carried by the armature 40 of the main relay and continues via the line 51 through the armature 52 of the protecting relay r associated with the adjacent end of block A", thence via the line 53 through the battery 54 to the line 55, through the protecting magnet '36 associated with the adjacent end of the block A3, line 57, through the semaphore magnet 58, and line 59, hack to the strip 50. It will accordingly be seen that associated with each main circuit are two line circuits, each normally closed by the armature of the main relay, and each line circuit being under the control of a protecting relay in the adjacent block, and itself controlling signal means in the other adjacent block, or between that block and the block under consideration.`

Associated with each line magnet is a contact plate adapted to be engaged by the locomotive brush and suitable conductors and a source of current. Thus, associated with the line magnet 46 is the contact plate 61, line 62, connecting the same with the ar mature 63 of the line magnet. From such armature runs a line 64, through a battery 65, to a line 66, to a strip 67, extending baekwardly from the armature 52 of the protecting relay r. The line 66 is normally out of contact with the strip 67. From an adjacent point 'extends a line 68, also normally out of contact with this strip, to the rail X of block A. Similarly associated with line magnet 56 is a contact plate 71, from which leads a line 72-through the armature 73 to the line 74, through the battery 75, to the line 76 which may be connected bya strip 77 on the armature of the protecting relay R3 with a line 78 returning to the rail X of block A3.

From the above description, it will be seen that each contact plate 61 and 71 is normally disconnectedh from the track but is adapted to be connected therewith by the corresponding protecting relay, provided the circuit is not open at the armature of the line magnet. As stated, the circuits through the line magnets are normally closed. Means are provided, hereinafter described, whereby when a locomotive is about to engage the contact plate, it first operates the protecting relay to complete the circuit from the armature of the line magnet to the track. When so completed, the brush on the locomotive engages the contact plate and the contact plate operates the circuit breaking lever on the locomotive. If now, the block in advance is clear, the line circuit is in normal condition and the connection from the contact plate to the rail is complete, so that before the circuit breaking lever opens the normal locomotive circuit a substitute eircuit is provided via the contact plate and its connection to the rail, and from the rail through the wheels of the locomotive to the locomotive frame and signal, and through a battery between the contact plate and rail. Accordingly, the locomotive signal magnet continues energized and the signal remains at safety. If, on the other hand, there were a train standing on block A2, the same would short circuit the main battery 30, and the armature 40 would open the two line circuits to the magnets 46 and 56, which would open the lines from the contact plates to the rail at the armatures of these magnets so that the protecting relays could not close them, wherefore, there would be no substitute source of encrg Y provided when the locomotive battery is cut out, and the locomotive signal would go to danger, when the brush engaged the contact plate 61 or 71, according as the locomotive is approaching from the left or right. The same result would talee place if one of the rails of block A2 were broken, denergizing the main magnet, or if lthe line circuit were broken or short circuited, or if the prot-ecting relay failed to operate, or if any of the batteries should give out.

The track semaphore is controlled b v a magnet as, 48 or 58, which is in series with the corresponding line magnet and operates UC' in unison with it. Magnet 48, for example, normally holds closed a circuit through a battery 8f), which operates to hold at safety a semaphore arm 81. The arm is counterweighted to give it a tendency to go to danger, which result takes place when the circuit through the battery 80 is opened. 'hen this circuit is closed, it operates a suitable motor (not shown) in the sema- 1 phore standard, which pulls the arm to safety and there magnetically holds it. It will accordingly be seen that Whenever a train is standing on any block, the semaphores at the two ends thereof show danger to oncoming trains from either direction, while the connection from the corresponding contact plates is such that an oncoming locomotive will receive a danger signal. It is essential, however, to protect each block before a train enters it, for if two trains entered an otherwise clear block at the same time, the change of the semaphore signal to danger would come just as the locomotive was passing it, and would give no available signal to such locomotive; or if such change in the semaphore signal were observed by the engineer, he could not tell Whether it was caused by his train or the train at the other end. Furthermore, where the locomotive cab signal is employed and each block is automatically tested a sufficient distance in advance to allow the train to stop before entering the block, it is essential that `such block be protected at the far end at the time of the test and held protected thereafter until the testing train actually enters the block, and to provide against the contingency of two approaching trains striking their testing contact plates at the same instant the block at the far end should be pro-V tected before the train tests it. For this purpose, I provide the locking relays and circuits heretofore referred to, and which I will now describe. l i

The contact plates, as 61 and 71, are preferably of such length and located such distance in advance of the beginning of a block that there is time after a locomotive encounters the plate to stop with the brush still in Contact with that plate, or, in place of having a continuous plate, there might be a subsequent plate electrically connected with the main plate. Accordingly, the beginning of the contact plate is preferably several hundred feet from the beginning of the block, and the protecting circuits have points where they may be affected by an oncoming locomotive' in advance of such distance, the. circuits overlapping into the adjacent block and being adapted to be affected a fier the locomotive enters such bloc-k.

The line circuit via lines 41 and 51 include as essential elements the armatures 42 and 52, by which I mean that these armacircuits. Each of these armatures is controlled by a double-acting relay of which there are two for each block, one near each end thereof, the relays in block A2 being designated R2 and r2, and the two relays shown in the adjacent ends of the blocks A and A3 being designated r and R3 respectively.

All of the protecting relays are identical and only one need be described. Take for example, the rela-y 1" at the right hand end of block A,-this relay operating the armature 52. This relay includes a pair of magnets 90 and 91, which tend to pull in opposite directions on the armature The magnet 90, it will be seen is on a closed circuit, including lines 93 and 94, each of which connects vv ith one of two short exposed contact plates d', the two contact plates being connected by a line 95 passing through a battery 9G. Normally, this battery is therefore on a closed circuit through the magnet 90, and holds the armature in the position shown. A suitable brush centrally located on the lccomotive (as 13, Fig. 2) bridging the two contact strips d would short-circuit this battery and denergize the magnet 90, allowing the armature to drop.

The magnet 91 is on a circuit composed of the lines 97 and 98, the two short contact plates d, the lines 99 and 100 leading from these contact plates to two other short contact plates (Z3 which are located at the junction of the two blocks, these latter contact plates being connected by a line through a battery 101. This battery normally maintains the magnet 91 energized, but this energization is lost whenever the brush 13 on the locomotive bridges the contact plates d2, short-circuiting the battery 101. These magnets 90 and 91 are so arranged that either will draw the armature to it when the other is denergized, but when both are energized, the armature will remain at the nearest magnet.

Fig. 2 shows a contact brush 18 carried by the locomotive and adapted t0 bridge the pairs of contact plates cl, d', d2, and short circuit the corresponding batteries. This brush has no electric connection with the locomotive circuit; and in place of having exposed contact plates which the brush bridges, there might be terminals operated by the passing locomotive in other manner to short circuit the battery, the essential being that the passing locomotive short circuits the battery. Thebattery is first short-circuited at the plate d for magnet 91, then at the plates fl this short circuit is opened and the battery for magnet 90 is short-circuited, then, as the brush clears these plates, this latter short-circuit is opened, and finally at the plates d2 the iirst battery is again shortcircuited. The purpose of this will be clearly seen from a description of the operation. Now, with the circuits described, suppose trains are approaching block A2 from blocks A and A3. The first train to reach the contact plate 61 or 71, as the case may be, would receive no signal, because the block A2 is unoccupied, but before the train reaches such Contact plate, it encounters the protecting plates d and d referred .to. We will consider the train on block A. lVhen the brush 13 on the locomotive of this train engages the plates d, the battery 101 is shortcircuited, from the magnet 91, but no change results for the armature is already held by the magnet 90. lVhen, however, the brush 13 engages theeontact plates d', the battery 96 is short-circuited, the magnet 90 denergized, and the armature drops to the magnet 91, thus breaking the circuit along the lines 51 and 55. This denergizes the lineV magnet 56 and the semaphore magnet 58 beyond and adjacent to the other end of the block A. Accordingly, as soon as a locomotive encounters the plates d for any block,

the block in advance thereof becomes therebfy protected at its far end. After the protec ing of the block A2 at the far end, the locomotive on block A comes into coperation with contact plate 61, by which it automatically tests the condition in block A2, as

already described. If block A2 is occupied, a danger signal is given in the cab, in addition to the danger signal provided by the semaphore. If block A2 is not occupied, both signals show safety. If the signals show safety, the engineer continues his run and passes onto block A2. In so doing, the brush 13 engages the contact plates d2, shortcircuiting the battery 101 and denergizing the magnet 91. Accordingly, the magnet 90 (which became energized as soon as the brush 13 cleared the plates d) picksup the armature 52 and restores the circuits at the protecting relay to normal position. Before this restoration takes place, however, the wheels of the locomotive will have passed onto the block A2 and short circuited the main battery 30 thereof so that the main relay opens and the signals at the far end of the block are maintained at danger, and the signals at the entered end are set at danger, by reason of the line circuits being open at the main relay. It will accordingly be seen that before any locomotive tests a block in advance, by the engagement of its brush with the contact plate as 61 or 71, such block has become protected at the far end by such locomotive operating the protecting relay, and that such protection continues until after the locomotive has entered the block, and that by so entering, the block is held protected at both ends by the main relay until the train has cleared the block.

If the train on block A encounters a danger signal as it is about to enter block A, either by the semaphore or by the locomotive signal testing the plate 61, or both, the engineer stops, and if he normally has the right of Way, may leave the train standing to watch for a safety signal, either by means of the semaphore or by his cab signal. The eab signal is constantly connected to show safety when the block becomes clear .by reason of the locomotive brush 12 remaining on the plate 61 or on an extension of that plate, electrically connected to it.

If the engineer who has stopped on block A does not normally have the right of Way, he backs the train after stopping, and in so backing short circuits first the battery 96, denergizing the magnet 90`(\vhich operation is idle, as the magnet 91 is already holding the armature), and then, as he comes onto contact plates d, relieves that short circuit and short circuits the battery 101, deenergizing the magnet 91 and allowing the battery 96 through the magnet 90 to restore the armature 52 to normal position, as shown in Fig. 1. This leaves the line through the line magnet 56 and semaphore magnet 58 in block A3, in condition to show safety, so that the train on block A3 may enter block A2.

The diagram in Fig. 1 shows a line magnet 106, corresponding to the magnet 56, but associated with block A', and a semaphore magnet 108 in series therewith. and corresponding to the magnet 58. These magnets 108 and 58 operate circuits through batteries 110 and 60 respectively, which operate corresponding semaphore arms 83 and 84. The diagram shows the semaphore magnet 118 on the line circuit for block A3, this magnet operating the circuit to control the semaphore arm 82. The arms 81 and 83 may be mounted on one semaphore standard, and the arms 82 and 84 correspondingly mounted, as is well understood.

The main relay located adjacent to the right hand end of block A is omitted in the diagram for clearness, so also 1s the main battery located at the left hand end of block'A.

' It remains to describe the special provisions of the locomotive circuit, as shown more clearlv in Figs. 3 and 4.l The purpose of these is to give the engineer an attention signal whenever the signal proper changes from safety to danger, or vice versa, and to prevent improper signaling, if there should be a short circuit at the circuit breaking lever, or if such lever should stick in its elevated position. As already described in connection With Fig. 2, the locomotive signal magnet 2 is in a normally closed circuit through a battery, and through a contact plate 7 on an operating lever 8. In practice, there are two operating levers, one on each side of the locomotive, and the circuit passes in series through the contact plates on the tWo levers, so that when either operates, it opens the circuit at that point. Thus, 1n Fig. 3 the line 3 from the magnet 2, has two ICI branches, one by way of the line 20 the contact spring 21 associated with the contact segment 7 on the lever 8, shown in the upper part of Fig. 3, and thence via the line 23 connected with this contact segment to the contact segment 7 on the other lever, thence via the spring 6, and the line 5 through the main battery 1.

After leaving the main battery 1, the line divides,-one part 10 going to the frame of the locomotive, and the other part 24 itself branching,-one half 25 going to the short segment 26, insulatingly carried by the lever, thence to the spring 27 to, the line 28, to the line 4; the other half going via the line 29, to the segment 19, thence to the spring 18, to the line 17, which joins the line 28, and forms the line 4, which passes back to the signal magnet. Each of the levers 8 is thus formed to make a double circuit breaker, as shown more clearly in Fig. 4, which represents the lever in normal position.

On the lever 8, beyond the insulation in which the segment 7 is set is a short metallic tongue 16, consisting of a portion of the lever itself, and on the other side of the tongue is a segment of insulation 15. The strip 7, the tongue 16, and the segment 15 all have a face concentric about the pivot of the levcr and are adapted to be engaged by the nose of the spring 6. The Segment 7 is connected by a flexible wire 23, above described` and the tongue 16, being a portion of' the lever itself, is grounded to the frame. The result is that when the lever swings in the direction of the arrow (Fig. 4), which it docs when the locomotive passes forwardly over the contact plate, the segment 7 moves from under the spring 6, opening the circuit at that point., and immediately shortcircuiting the battery, through the spring 6, tongue 16, lever 8, line 22, locomotive frame and line 10. Then the lever in its further swing brings the insulation 15 beneath the spring 6, continuing the circuit open at this point and breaking the short circuit about the battery.'

The construction described cuts out the locomotive battery as soon as the lever operates, and unless the track conditions are such as to provide a substitute circuit With battery, the signal goes to danger. Such substitute circuit, as heretofore explained, can only be provided when the track is clear, and all the track circuits and batteries are in working order, and when there is no cross-connection by leakage or otherwise from the contact plate. 1f the track is either occupied or anything wrong with any of the circuits or mechanism, the substitute circuit fails, and the signal magnet goes to danger as soon as the locomotive circuit is broken by the lever. Any metal filings or extraneous matter which might accumulate onv the plate 7 and possibly elect a connection to the spring 6 from that plate, after the plate has cleared the spring, are rendered inocuous, for the battery is at once shortcircuited by the tongue 16 engaging the spring, and after the tongue clears the spring, the plate 7 has moved a sufficient distance from the spring to absolutely prevent any cross-connection.

On the upper end of the lever 8, as shown in Fig. 4, is a segment of insulation 14, in which is set a small contact piece 19 which in normal position is engaged by the spring 18. It will be remembered that the connection from the line 24 to the line 4 is double, one half passing via the contact 19, and spring 18 of one lever 8, and the other via the corresponding contact 26 and spring 2 7 of the other lever 8. Accordingly, when either lever alone is moved, the circuit is preserved through such spring and contact of the other lever, but if both levers are moved, the circuit is broken. This provides against the system being rendered ineffective by reason of a lever sticking in its elevated position after trailing over a contact plate.

A suitable spring, (not shown), is provided to return the lever to normal position, and hence the conditions would be very eX- ceptional when it would stick. But, if, by any accident, one of the levers should stick in its elevated position after the locomo` tive has moved in the rearward direction over a contact plate and thus be out of position to engage the next contact plate, the engineers attention is called to it, for as Soo-n as the lever on the other side hits the next Contact plate, which it does almost irnmediately thereafter, the other leg of the circuit becomes broken by reason of the me` tallic piece 19 or 26 clearing the contact spring and the signal at once goes to danger. If, either lever -should stick when swung in the normal direction, the signal would go to danger as soon as the locomotive cleared the contact plate, by reason of the break at the nose of the spring 6.

To insure the engineers attention vbeing called to the fact that there is a change in his locomotive signal, either in going from a previous position of safety to one of danger, or vice versa, I provide a double-acting ringer operated by a magnet in a shunt across the lines 3 and 4 of the signal magnet. The magnet for this ringer is designated 120 and its two circuit lines 121 and 122. This magnet operates to attract an armature 123 which carries a hammer 124 which in the normal or attracted position stands close to the gong 125.

lVhenever the locomotive circuit is broken or the battery 1 short-circuited, the magnet 120 becomes denergized, and the spring 126 (adjusted by the screw 127) lforces the hammer against the gong 128, thus advising the engineer of a change in the condition of his signal. W'henever the signal goes to safety by reason of the circuit being restablished, the energization of the magnet 120, drawing back the armature 123 and the hammer 12.4L strikes the gong 125, there being a resilience in the stem connecting the hammer with the armature. Accordingly, when the signal goes to safety, a strike is given on the gong 125. If desired, the gongs may have a different sound by reason of being made of different size or material or ctlieiwise, so that the danger and safety strikes are differentiated. As shown, the safety gong 125 is smaller and hence has a higher pitch and is less loud than the danger gong 12S.

W'ith my complete system as above described, the engineer may run his train continuously with perfect safety, knowing that lie .will receive a danger signal whenever his train comes within a block of another train or n broken rail, or an open draw-bridge, or a misplaced switch, the latter being taken care of by a suitable connection, which either opens the main line or short circuits the niain battery when the switch is open. ffhe engineer also receives a danger signal if thereis anything out of order in the electric equipments. The cab signal is two-fold, audible and visible, and these may be supplemented by track scmaphores, whereby the protection is as complete as possible.

Having thus described my invention, I claim:

1. The combination of a track divided into blocks, a main track circuit for each b lock, two line circuits for each block track signalscontrolled by the line circuits, two protecting circuits for each block one near each end of the block, each protecting circuit which is located near the end of one block controlling the line circuit whose signal is near the adjacent end of the next block but one, said protecting circuits being under the control of passing locomotives, said track signals being located adjacent to the ends of blocks, and means controlled by the line circuits and between the track sign als 'and the points where the protecting circuits are first affected by approaching trains for giving a signal from the track to the locomotive. 2. The combination of a track divided into blocks, a locomotive circuit, protecting circuits, means apart from the rails whereby a passing locomotive may control the protecting circuits, track signals located ad- ]acent to the ends of blocks, and means between the track signals and the points where the protecting circuits are first affected by approaching trains for giving a signal from the track to the locomotive.

3. In an electric signal system, the combination of a railway divided into blocks, of

an installation for each block comprising a main circuit, two line circuits, and two protecting circuits, the line circuits being under the control of both the main circuit and the protecting circuits, a locomotive circuit, and means whereby it may be connected with the track, such means being under the control of the liiie circuit, and being located along the trackway adjacent to the end of a block for a sufficient distance to enable the locomotive to receive a signal before entering a block, and stop before entering `the block, while its circuit is still connected with the track. Y.

4. In an electric signal system, the combination of a railway divided into blocks, an installation for each block comprising a main circuit', two line circuits, and two protecting circuits, the line circuits being under the control of both the main circuit and the protecting circuits, and a track semaphore under the control of each of the line circuits.

5. The combination of a main track circuit, two line circuits governed thereby, a track signal governed by each line circuit, and means for giving a signal in a passing locomotive, a normally closed protecting circuit, said means being governed jointly by the line circuit and by the normally closed protecting circuit, and means on a passing locomotive for operating the latter circuit.

6. The combination of a track divided into blocks, a main track circuit for each block, two line circuits for each block controlled by the corresponding main track circuit, track signals controlled by the line circuits, two protecting circuits for each block, one-near eaclrend of the block, the protecting circuit which is located near the end of one block controlling the line circuit whose signal is near the adjacent endof the next block but one, said protecting circuits being under the control of passing locomotives.

7` In an electric signal system, the combination of a main circuit connected with the track, a line circuit controlled thereby, la protecting circuit also controlling the line circuit, track-contact plates adapted to control Ythe protecting circuit, and a brush 0n the locomotive adapted to bridge such plates to short circuit the protecting circuit.

8. In an electric signal system, the combination with a track divided into blocksLa main circuit for each block, a pair of protecting relays for each block, line circuits under the joint control of'the main circuit and the protecting relays, two protecting circuits for each protecting relay, each of said protecting circuits having two exposed contact plates and a battery in a line connecting such plates, and means on a locomotive adapted to bridge such plates.

9. In anelectric signal system, the combination with a track divided into blocks, a main track circuit and line circuits controlled by the main track circuit, of protecting relays whose armatures also control the line circuits, pairs of Contact plates, conductors leading from such pairs to the respective protecting relays, and batteries connected therewith. and adapted "te 'oe sliertcircuited when Aai bridge esfaiisffed across such pairs of platre.

l0. 1n an @Effet guai system, 1Q-:Xe com.- biriaticn with neqtrsekc uit and line circuits controied thereby, of protectingrelays haring armatures also controlling the line circuits, each relay having two oppositely acting magnets with independent circuits, each relay circuit connected with a pair of contact plates adapted to be bridged b v means of a moving vehicle.

In Vtestimony.' whereof, I-hereunto afix my signature i'n the presence of two Witnesses. 

